A. Field of the Invention
The present invention relates generally to voice over packet based networks, and more particularly, to SIP communication networks.
B. Description of Related Art
The transmission of voice and video over packet based networks, as compared to traditional dedicated-line telephone service, provides the possibility of significantly cheaper and more flexible voice and video connectivity.
SIP (session initiation protocol) is a signaling protocol for initiating, managing and terminating voice and video sessions across packet networks. SIP sessions involve one or more participants and can use unicast or multicast communication. Borrowing from ubiquitous Internet protocols, such as HTTP and SMTP, SIP is text-encoded and highly extensible. SIP may be extended to accommodate features and services such as call control services, mobility, and interoperability with existing telephony systems.
At certain times, telecommunication providers may wish to connect a calling party to a prerecorded announcement. For example, if the calling party dialed an invalid number, the telecommunication provider may wish to connect the party to an announcement that informs the party that the number is not recognized. Under the conventional SIP protocol, there is no provision for the effective playback of a such announcements.
Some solutions do exist for providing prerecorded announcements via the SIP protocol. These solutions tend to use one or more SIP messages for each pre-recorded announcement, or portion of the pre-recorded announcement. These solutions can be become quite message intensive, and are thus inefficient in handling announcements through SIP.
Accordingly, there is a need in the art to improve announcement playback in a SIP telecommunications network.